Attachment plug



' S. MCCLATCHIE ATTACHMENT PLUG Filed July 3, 1920 Patented Feb. 2,1926. y

UNITED STATES PATENT oEFlcE.

STANLEY MCCLATCI-IIE, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO BENJAMINELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OFILLINOIS.

Application tiled July 3,

To all whom it may concern:

Be it known that I, STANLEY MCCLAT- Crim, a citizen of the UnitedStates, residing at Cambridge, in the county of Middlesex and State ofMassechusetts, have invented new and useful Improvements in AttachmentPlugs, of which the following is a full, clear, concise, and exactdescription, reference being had to the accompanying drawing, forming apart of this speciiication.

My invention relates to electrical connector devices, and morespecifically to swivel attachment plugs.

One of the objects of my invention is to provide a swivel attachmentplug, which will be etlicient and durable in use, easy to wire, simplein construction and cheap to manufacture.

Further objects will appear from the detailed descriptionto follow andthe appcnded claimsV In the drawings in which an embodiment of myinvention is shown,"d

Fig. 1 is an axial section of an attachment plug;

Fig. 2 is an axial section on the line 2 2 of Fig. 1;

Fig. 3 is a. plan view of the plug;

Fig. l is a transverse sectional view of the plug on the line 4l-fl ofFig. 1;

Fig. 5 is a transverse sectional view of the plugou the line 5 5 of Fig.1.

The construction shown in the drawing comprises in a. general way anattachment plug having shell and center contacts 10 and 11 respectively,wiring terminals 12 and 13 for the contacts 10 and 11 respectively,

an insulating handle or thumbpiece 14E detacha-bly secured to thethreaded shell contact 10 and an insulating base 15 for supporting thecenter contact 11 andthe binding terminals 12 and 13 and for insulatingthe center contact 11 from the shell con tact 10.

In order that the threaded shell contact 10 can be screwed into a socketwithout twisting the cords secured to the binding terminals 12 and 13, aswivel connection is provided between the insulating base 15 whichsupports the wiring terminals and the threaded shell contact. Thisswivel connection is effected by providing the threaded 1920. Serial No.393,972.

shell contact 10 with an annular channel portion 16, in which isswiveled an annular' swivel contact member 17, which is secured to anannular flange portion 18 ofthe insulating base 15. This annular swivelcontact member 17 may be formed as a part of an integral sheet metalstamping having a conducting strip portion 19 extending downwardlytherefrom and secured to the binding plate member 2O of the wiringterminal 12 in any suitable manner, as by means of rivets 2l.

The center contact 11 may be formed as a" flange portion of a tubularexternallythreaded eyelet member 22 secured in place on the insulatingbase 15 by means of a nut 23. This nut 23 also serves as-a binding platemember, the bared end 24 of the feed wire being clamped against this nut23 by means of another nut 25, which is also threaded onto the eyelet22.

In order that the bared end 241 of the feed wire may be secured in placeunderneath the nut 25, both the eyelet 22 and the upper nut 25 areslotted as indicated at 26 and 27 respectively. In wiring this terminal13, the bared end 24 of the wire is passed up through the eyelet 22, theupper nut 25 is turned until the slot 27 registers with the slot 26 inthe eyelet, the end of the wire is bent over and drawn down throughthese slots to a. position underneath the nut 25, and y,

the end is then Vwrapped around` the eyelet,

and the screw 25 is screwed down to clampV the wire between the nuts 23and 25.

In order to relieve the wiring terminal 12 from strain, the insulatingbase 15 is provided with an integral yokeshaped portion 27 a (Fig. 1)comprising a cross-bar or saddle portion 2S (Fig. 2) over which the feedwire 29 is looped, the bared end 30 of this feed wire being brought downand secured down underneath the head of the binding screw 31.

This cross-bar 28 and the opening for the eyelet member 22 are soproportioned as to facilitate the die-molding of the insulating base 15.As shown in Fig. 2, the width of the opening for the eyelet 22 is thesame as the width of the cross-bar 28, so that a projection on the upperdie can enter between two side faces of the lower die and slide alongthese faces, the upper face ofthe cross f bar 28 being formed by thelower face of this projection on the upper die.

In order to detaehably connect the insu'- lating thumb-piece 14 to thethreaded shell contact 10, the insulating thumbpiece is provided with anexternally-threaded ,annular flange portion which is threaded into thelower end of the shell contact 10. In order to prevent the thumbpiece 14from accidentally becoming disconnected from the threaded shell contact10,l the thumbpiece is provided with a recess 33 into which extends aprojection Sel: struck up from the `lower portion oit the threaded shellcontact 10. lVhen it is desired to disconnect the thumbpiece from thethreaded shell contact, the projection 34 can be readily disengaged fromthe recess 83 to permit the thumb piece to be unscreu'ed from thethreaded shell contact.

The annular sliding contact 17 is secured in place in the channelportion 16 by lang ing over` the upper edge of the threaded shellcontact member after the parts are in assembled position. After theparts arek once thus assembled, it is not necessary to disconnect thethreaded shell contacty from the sliding Contact member 1T ior Wiring,as the vWiring can be accomplished Without this disconnection. In Wiringthe device the insulating thumpiece 11iis unscreived rfrom the threadedshell Contact 10 and slipped on over the ends ot the 'feed Wires. Oneo't the feed Wires is then slipped up through the cyelet 22 and securedin place underneath the nut i5 as previously described. r[he other feedWire is looped over the crossbar or saddle 25 and the ends brought doivnand secured underneath the head of the binding screw 31. The thumbpiece14 is then slipped up on the feed Wires and screwed into the threadedshell contact 10, the projection Sii snapping` into place into therecess 33 to prevent the parts from coming unscreived. In screwingthethreaded shell contact m the socket the cord will not be twisted as theinsulating base 15 which supports the Wiring terminals for the cord hasa swivel connection with the threaded shell contact.

Having thus described my invention, What I claim as new and desire tosecure by Le'.- ters Patent is:

1. An attachment plug comprising a side contact, a tubular member havinga portion forming a center Contact, the bore of the tubular memberproviding a passage for the conductor for the center contact, and saidplug having provisions for securing said conductor comprising a nutthreaded-on said tubular member.

,2. An attachment plug comprising a side contact, an insulating bodyWithin said side contact, a tubular metal member extending through saidbody, said tubular member having a portion forming a center contact, thebore ot said tubular member a'ording a passage for the conductor, saidtubular member being provided With a lateral passage 'for the conductor,and means for securing the end of said conductor, comprising a nutthreaded on said tubular member.

3.. An attachment plug comprising side and center contacts, and a bodyot insulating material comprisingl a cap portion for supporting theshell and center contacts in proper position with respect to each otherand insulating them `from each other, and a yoke portion extending fromsaid cap portion, and a Wiring terminal supported by said yoke portion,the cross-bar of said yoke alibi-ding a strain relief means over whichythe conductor leading to said Wiring terminal is looped, said capportion having an opening in which the center contact is secured, saidopening being in alignment with and leading to the opening above thecrossbar of the yoke port-ion in which the center contact is secured. y

In Witness whereof', I have hereunto subscribed my name.

STANLEY MCGLATCHIE.

